1. Field of the Invention
This invention relates to third degree acyclic esters of phosphorus acid, i.e., compounds containing three P--O--C linkages.
2. Description of the Prior Art
Haloalkyl phosphates are known flame retardants, see U.S. Pat. Nos. 3,132,169; 3,287,266; 3,324,205; and 3,830,886. Commercially known haloalkyl phosphates include tris(bromochloroisopropyl)phosphate, tris (2-chloroethyl)-phosphate, tris(dichloropropyl)phosphate, and tris(2,3-dibromopropyl)phosphate, see 1974-1975 Modern Plastics Encyclopedia, McGraw-Hill Inc., New York, New York, p. 755 et seq. It has been discovered that a sub-generic group of haloalkyl phosphates possesses increased hydrolytic and thermal stability over other haloalkyl phosphates. This improved hydrolytic and thermal stability enables the haloalkyl phosphates of this invention to impart flame retardancy of increased durability to materials treated therewith.